/* //flex */
html,
body {
    height: 100%;
    margin: 0;
}

.wrap {
    display: flex;
    min-height: 100%;
}

.left {
    background: lightblue;
    flex-basis: 200px;
}

.content {
    background: lightpink;
    flex-grow: 1;
}

.right {
    flex-basis: 200px;
    background: lightgreen;
}
/* //grid */
html,
body {
    height: 100%;
    margin: 0;
}

.wrap {
    display: grid;
    min-height: 100%;
    grid-template-columns: 200px auto 200px;
}

.left {
    background: lightblue;
}

.content {
    background: lightpink;
}

.right {
    background: lightgreen;
}
